Lever-cam operated, slidable jaw wrench



March 27, 1962 w. K BERGMAN 3,026,751

LEVER-CAM OPERATED, SLIDABLE JAW WRENCH Filed Aug. 18, 1960 2 Sheets-Sheet 1 WA w K BEAGM/W INVENTOR.

BY y fijmg ArraR/V' Y March 1962 w. K. BERGMAN 3,02

LEVER-CAM OPERATED, SLIDABLE JAW WRENCH Filed Aug. 18, 1960 2 Sheets-Sheet 2 WA y/vz K BERG/4AM INVENTOR.

HTT AIV Y tlnited States Patent 3,026,751 LEVER-CAM OPERATED, SLIDABLE JAW WRENCH Wayne K. Bergman, 927 Butler St., Toledo, Ohio Filed Aug. 18, 1960, Ser. No. 50,375 4 Claims. (Cl. 81129) This invention relates to valve wheel wrenches or spanners and more particularly to a wrench or spanner that employs cams and cam action to compress the normal gripping jaws when lateral force is applied to the handle or lever.

In general the device of the present invention consists essentially of a lever or handle terminating in a dual or bifurcated end portion which in turn is pivotally connected to two alined gripping jaws by means of an adjustable threaded bolt that adjusts the vertical position of the lower gripping jaw. The upper gripping jaw as well as the upper arm of the bifurcated end portion are provided with mating cam surfaces alined so that when lateral pivotal force is exerted on the lever in either direction, the cam surfaces unmate, and the result is a forcing of the upper jaw toward the lower jaw; thus resulting in the jaws firmly gripping the valve wheel handle between them. Any further lateral force on the lever will result in the rotation of the hand wheel towards either its open or closed position.

New, useful and important advantages can be obtained from the use of this particular cam action in the wrench design of the present invention that manifestly makes this invention a substantial improvement over existing similar devices and a vast step forward in the field of wrenches, particularly those used to rotate valve hand wheels or the like.

One object and advantage of the present device is that it is cheap and relatively simple to manufacture, hence, economical to purchase. Also, the design is such that it can readily be constructed in various sizes to cover a wide variety of hand wheel sizes as well as shapes. Also because of the great flexibility in adapting itself to a wide variance in sizes and shapes, a single wrench can be used where in the past several were required.

Another object and advantage of the present device is that the lateral movement of the wrench lever exerts both a gripping action on the jaws through the cam action while at the same time exerting a rotation force on the hand wheel. Any increase of lateral force on the wrench lever both increases the compression force of the jaws on the hand wheel surface as well as increasing the rotation force exerted to rotate the hand wheel, thus giving greatest operating efficiency as well as safety, for at the point at which greatest rotating force is being applied, the maximum compression force is being exerted by the jaws, thus preventing dangerous slippage.

Still another object and advantage of the present device is that through the employment of cam action in the present invention a powerful acting wrench is produced with a lever that can be moved alternately back and forth, and the gripping and turning of the hand wheel by the jaws can be accomplished by the lateral movement of the wrench lever in either direction, and the result is that from the same wrench position on a hand wheel the direction of rotation of the hand wheel can be instantly changed.

A still further object and advantage of the present device is the obvious simplicity of construction which does with a simple cam action what normally would require complicated mechanisms to accomplish the same positive and safe results.

In the accompanying drawings forming a part of this specification,

FIGURE 1 is a front elevation of the valve wheel cam wrench in the open or non-gripping position,

FIGURE 2 is a side elevation of the valve wheel cam wrench in the same open or non-gripping position,

FIGURE 3 is a top view of the valve wheel cam wrench in the closed or gripping position, and

FIGURE 4 is a side elevation of the valve wheel cam wrench in the same closed or gripping position.

Now referring in more detail to the accompanying drawing in order to more clearly define the present invention, in general the preferred valve wheel cam wrench consists of an elongated handle or lever portion 1 to enable increased leverage or turning moment to be exerted on its bifurcated end portion 2. The length and dimensions of the handle or lever portion 1 can be varied depending on the size and leverage desired. The bifurcated end portion 2 has two arms: upper arm 3 and lower arm 4.

The upper gripping jaw 5 and the lower gripping jaw 6 are pivotally connected to the bifurcated end portion 2 by means of flatsided, threaded, adjusting bolt 7 which is integral with and forms an elongated vertical extension from lower gripping jaw 6. The bolt 7 extends upwardly through a circular aperture in each of the upper and lower arms 3 and 4 to permit the bolt 7 to rotate within these apertures. The bolt also extends through a flat sided or non-circular aperture in the upper gripping jaw 5 which aperture is designed so that the bolt 7 cannot rotate within the upper jaw 5 but will in eifect rmult in the upper gripping jaw 5 and the lower gripping jaw 6 always being in the same lateral alignment and always moving laterally together as a unit. However, the bifurcated end portion 2 may pivot laterally, independently of the gripping jaws 5 and 6 due to the circular apertures in arms 3 and 4, which permit the bifurcated portion 2 to partially pivot around the flatsided bolt 7.

A knurled nut 8 is screwed on the top protruding end of bolt 7 to prevent the integral lower jaw 6 and flatsided bolt 7 from slipping downwardly. A pair of comprmsion springs 9 and 10 surround the bolt 7 at two positions. Upper compression spring 9 is positioned between the lower arm 4 and the upper jaw 5, thus tending to hold the upper jaw 5 away from the lower jaw 6 and upwardly against the cam of upper arm 3; and lower compression spring 10 is positioned between lower gripping jaw 6 and the lower arm 4 thus forcing the lower jaw 6 away from upper jaw 5.

The underside of the upper arm 3 is formed into ring cam 3C which is designed to exert pressure on the upper side of the upper gripping jaw 5 which is formed into a matching or mating ring cam S-C which also is designed to closely receive and mate with ring cam 3C.

In more detail the working or mating surfaces of the cam portions 3-C and 5C are preferably parallel throughout the entire cam surface. In the Wrenchs open or non-gripping position as shown in FIGURES 1 and 2 the dual antilines or hills of each cam mate perfectly with the corresponding dual synclines or valleys of the other cam. This permits the gripping jaws 5 and 6 to be in their opened or non-gripping position. When the gripping jaws S and 6 are engaging a valve hand wheel or the like and the handle or lever 1 is pivoted laterally in either direction, right or left from center position, the ring cam surface 3-C begins to mismate with ring cam surface S-C, making the hills of the two ring cams climb each other as in FIGURE 4 with the result that the upper jaw 5 is forced down towards the lower jaw 6 exerting tremendous compression and turning force on the valve hand wheel. The greater the lateral or horizontal force on the handle 1, the greater the compression and turning force exerted on the hand wheel by the jaws 5 and 6.

The more detailed and preferred construction of the jaws and 6-would have the jaws 5 and 6 shaped as shown in the accompanying drawings. The upper jaw 5 when viewed from the top as in FIGURE 3 is tapered so that the sides from a triangle. The front portion of the jaw 5 is preferably arcuate. The lower jaw 6 if viewed from the underside would have substantially a similar exterior contour. The jaws 5 and 6 when viewed from the side as in FIGURES 2 and 4 are each constructed with a similar arcuate recess or groove extending the entire width of the jaw with the length of the recess or groove being arcuate to better accommodate normally circular hand wheels and the surface or periphery of the grooves S-R and 6R also being arcuate to better accommodate and partially surround the normally round surface of hand wheels such as shown by numeral 12.

It should be undersotod that while the prime purpose for this hand wheel gripping wrench is to open and close valve hand wheels, that by varying the contour of the grooves in the jaws, that other uses including that of a pipe wrench are anticipated. In fact as long as lateral or horizontal force is exerted on the handle 1 to maintain compression of jaws 5 and 6 on a pipe or a hand wheel or the like, vertically or up and down force exerted on the handle 1 will permit the turning force on the pipe or hand wheel surface to be transmitted in the same direction. In this way, by providing the recesses or grooves S-R and 6-R with both longitudinal and transverse serrations or teeth S-T and 6T the wrench of the present invention can be used to turn wheels or to pull or push or bend pipes and rods or similar objects.

Explaining in more detail the preferred construction of some of the elements of the wrench of the present invention, it should be pointed out that the entire length of bolt 7 is non-circular and preferably flat on two sides and that at least the entire maximum top protruding portion of the bolt 7 has right-handed, coarse threads 7-T for fast adjustment between upper and lower jaws 5 and 6 when raising or lowering lower jaw 6 to fit various thicknesses of hand wheels.

As previously stated lower compression spring is compressed, and lower gripping jaw 6 is raised for adjustment by turning knurled nut 8 clockwise on the protruding threaded portion 7-1 of bolt 7. A washer 11 is preferably placed between the nut 8 and the upper arm 3. Also slight recesses should be provided in the undersides of lower arm 4 and the upper jaw 5 to better center and receive the compresison springs 9 and 10 when compressed.

The preferred design of cams 3-C and S-C consists essentially of a circular periphery if viewed directly from above or below with apertures in the center for receiving bolt 7. The working or mating surfaces of each cam preferably are matched at all points. The periphery of each cam is preferably divided into four equal quadrants with the high point of one anticline or hill in the center of the first quadrant, arcuately and gradually blending into the low point of the syncline or valley in the center of the next quadrant, which again rises to the high point of the next hill in the center of the next quadrant and then lowers to the low point of the next valley in the center of the fourth quadrant. Thus, there will be two hills on one cam in mating position with the two valleys on the other cam when the jaws are in the open or noncompressing or non-gripping position as shown in FIG- URE 1. In the gripping or compressing position as shown in FIGURES 3 and 4, the dual hills of each cam unmate and proceed to climb the hills of the other, thus forcing the vertically movable upper jaw 5 downward into its gripping or compression position.

To better explain the operation of the wrench of the present invention, a brief description of the way the wrench would be used will be given. When the wrench is to be used to turn a valve hand wheel or the like, the first operation would be to loosen knurled nut 8 by rotating it counter-clockwise. This, through the tension of lower compression spring 10, will drop or lower the lower jaw 6 to its maximum open position depending on how far the nut 8 is moved up on the protruding top end 7-T of flatsided bolt 7. Upper compression spring 9 will hold the upper jaw 5 centered and upwardly so that the cam surface 5-C of the upper jaw 5 will be forced against and in a mating position with the cam surface 3-C of the upper arm 3 which is the full open position for upper jaw 5.

The wrench gripping jaws 5 and 6 are placed above and below the valve hand wheel with the lever 1 in center position. The nut 8 is now turned clockwise compressing the lower compression spring 10 and forcing lower jaw 6 up until both upper and lower jaws 5 and 6 are snug against the upper and lower periphery of the hand wheel. The serrations or teeth 5-T and 6-T create additional holding or friction pressure to prevent slippage of the jaws 5 and 6 over the hand wheel surface.

Once the jaws are as snug as the turning of nut 8 will produce by normal finger pressure on the nut 8, the major gripping force is applied by moving the handle or lever 1 laterally in either direction. Only a fraction of turn of the lever 1 will be sufficient to cause the ring cams 3-C and 5-C to mismate making the anticlines or hills of each cam climb one another, thus forcing the upper jaw 5 in a downwardly direction towards lower jaw 6 exerting tremendous compression or gripping pressure on the surface of the gripped hand wheel. Further horizontal or lateral movement of the lever or handle 1 will now exert turning pressure on the hand wheel causing it to rotate in the desired direction. Either opening or closing of a valve hand wheel can be accomplished without changing the gripping position of the wrench jaws 5 and 6 on the hand wheel surface or turning the wrench over by merely moving the handle or lever 1 either right or left from the center position. This is a necessary and desirable action if the wheel is to be alternately opened and closed without moving or turning over the wrench.

From what has already been described, it is manifest that the hand wheel cam wrench comprising the present invention is a new and important improvement in wrenches in general and hand wheel gripping wrenches or spanners in particular. Therefore, having described the invention, the following is claimed:

1. In a wrench of the class described, a lever, a bifurcated end portion on said lever and, a cam portion on said bifurcated end portion; a pair of gripping jaws pivotally attached to said bifurcated end portion, a cam portion on one of said jaws cooperating with said cam portion on said bifurcated end portion, so that when the lever is laterally pivoted in either direction the force impartedto said gripping jaws is perpendicular to the plane of movement of said lever causing the cam portions to force said gripping jaws together when said cam portions are forced beyond their mating position by the lateral movement of said lever in either direction.

2. The combination of claim 1, with each of said cam portions having a circular periphery and the mating surface of each of said cam portions having alternating dual hills and valleys arcuately blending into each other so that the low point of said valleys and the high point of said hills are separated from each other by substantially degrees on said circular periphery of each of said cam portions, and the entire mating surface of each of said cam portions being parallel and both of said cams being normally positioned in the mating position, so that said hills of one of said cam gportions mate with said valleys of said other cam portion, and when said lever is pivoted said hills of one of said cam portion are forced out of the valleys of said other cam portion forcing said gripping jaws closer together.

3. In a device of the class described, a lever, a bifurcated end portion on said lever consisting of an upper and a lower arm, an upper gripping jaw disposed between the two arms and a lower gripping jaw disposed beneath said lower arm, a forward gripping end portion on each of said gripping jaws, a threaded flat-sided bolt extending vertically and upwardly from said lower gripping jaw rear end portion and passing through apertures provided in both of said arms and said upper gripping jaw rear end portion, said apertures in said arms being circular to permit pivoting around said bolt and said aperture in said upper jaw rear end portion being noncircular and shaped to snugly fit said non-circular bolt, and said non-circular bolt extending beyond said upper arm aperture, an adjustable threaded nut on said bolt for adjusting the vertical position of said lower jaw, compression springs urging said upper and said lower jaws apart, a cam surface on one of said jaws, and a cam surface on one of said arms for cooperating with said cam surface of one of said jaws so that when the cam surface of said arm is urged out of mating position with said jaw cam surface by the pivoting action of said lever, that said jaw with said cam surface is forced towards said other jaw thus establishing the gripping action.

4. In a device of the class described, a lever handle, a bifurcated end portion on one end portion of and integral with said lever handle, said bifurcated end portion comprising an upper arm and a lower arm extending from said lever handle and separated from each other; a cam surface on the underside of said upper arm; an upper gripping jaw having a thickening rear portion and a protruding forward gripping portion; the upper surface of said rear jaw portion being cammed to mate with said cam under surface of said upper arm; a lower gripping jaw, a forward gripping portion on said lower jaw correspondingly to said upper jaw forward gripping portion, a flatsided elongated bolt with an upper threaded portion, and said bolt being integral with and extending vertically from the rear portion of said lower jaw and said bolt extending through circular apertures provided in the center of said upper and lower arms and a non-circular aperture provided in the center of said rear portion of said upper jaw, said circular aperture diameter being such as to snugly permit rotation within it of said bolt, and said non-circular aperture being such that it fits snugly around said bolt and permits vertical movement but no rotation movement of said bolt, so that the upper and lower jaws move laterally in alignment with each other; a threaded nut for screwing on said upper threaded bolt portion; a compression spring surrounding said bolt and positioned between said lower arm and said upper jaw rear portion to force said upper jaw upwards to hold it in continuous contact with said upper arm cam surface, another compression spring surrounding said bolt and positioned between said lower arm and said lower jaw rear portion to force said lower jaw downwards, said upper jaw and said lower jaw forward gripping portions each being provided with facing arcuate recesses for partially surrounding a circular pipe, a hand wheel or the like.

References Cited in the file of this patent UNITED STATES PATENTS 572,757 Jackson Dec. 8, 1896 601,015 Fitzgerald Mar. 22, 1898 1,194,271 Canfield et al. Aug. 8, 1916 1,326,172 =Boehm Dec. 30, 1919 1,974,105 Eagan Sept. 18, 1934 2,324,187 Arthur July 13, 1943 2,594,154 Greer et al. Apr. 22, 1952 FOREIGN PATENTS 15,214 Germany of 1882 

